Open/closed loop Jeckyl/Hyde

[akallotte at juno.com]

I think this is mainly an IAC problem, but I don't know what's causing
the spastic IAC.  In open loop, it's wide open and I've got low vacuum
and a lean condition.  Probably because the IAC is just a vacuum leak. 
In closed loop, the IAC closes and life is good.

Why is the IAC wide open in open loop?  I haven't changed my idle speeds
in the program, but my new mechanical idle is set slightly higher than
the eprom's commanded idle.  Why is it opening all the way up at 700 when
the car runs much better at 700 with it closed?

Am I missing something obvious?  Until I get some ideas, I think all I
can do is unplug the IAC and see what happens.

On Thu, 22 Mar 2001 22:35:25 -0500 "Bruce Plecan" <nacelp at bright.net>
writes: 
> Just some points to look at:
> That much cam is going to want more air at idle,  when cold is 
> probably
> going to want a richer mix.   Depending on driving sytle, you might 
> do
> better with the IAC at idle in drive warm, at 0.   The ecm uses the 
> IAC in a
> stall saver mode.
> 
> Takes tuning tinkerin experimenting to see exactly what your engine 
> wants
> Bruce

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